Vat dyestuffs of the violanthrone series and process of making same



Patented July 15, 1930 HUGO SIEBENBfi'RGER, OF BASEL,

OF CHEMICAL INDUSTRY IN BASLE, OF BASEL, SVJITZERLAND VAT DYE$TUFFS OF THE VIOLANTHRONE SERIES AND PRQCESSOF MAKING SAME No Drawing. Application filed July 21, 1925, Serial No. 45,095,

It has been found that new black-dyeing vat dye-stuffs may be obtained from monoa-minoviolanthrone, i. e. the reduction product of the substance disclosed under No. 1102 in the Colour Index, edited by F. M. Rowe, published A. D. 1924 in Bradford, Yorkshire, Great Britain, by the Society of Dyers and Colourists,

tints which remain unchanged by treatment with chlorine.

The constitution of the new products is not known but it is ,Very probable that the nuclear structure of the violanthrone skeleton is not attacked. Example 1 of 80% strength and and also in the U.; S. Pat

ent specifications Nos. 796,393 and 876,679,

obtained by acid of 10 per centstrength.

noviolanthrone,

finest state of subdivi and in Switzerland August 9, 1924.

parts of acetic acid the suspension 1s heated sion are suspended in 100 to about 95 C. added to the mixture by and by an aqueous solution of chromic spending with 2 per cent of CrO the chromic acid solution'has been added, the whole is kept at 95 C. for one hour, the dyestufi is then filtered, washed anddried. It forms a black powder, dissolving in sulfuric acid with dull bluish-red coloration. When poured into water, grayish-black flocks separate from the solution. The dyestuif dissolves in boiling nitrobenzene with slightly greenish blue coloration and yields a dull blue vat, dyeing cotton olive-black tints which are fast to chlorine.

500 parts of acid corre- E'zrample 2 '10 parts of nionoaminoviolanthrone cf. Colour Index N o. 1102, and S. A. Patents 796,393 and 876,679 in finest state of subdivision are introduced into 700 The suspension is'then heated at 95 C. and there are added by andjby at this temperature 300 parts of an aqueous solution containing 20 parts of sodium chlorate. The same temperature is maintained still for some hours and the dyestuflffiltered, Washed and dried. It'fornis a 7 black powder, dissolving in sulfuric acid with bluish-red, in boiling nitrobenzene with greenish-blue coloration. The dyestuif yields a blue vat, dyeing cotton black tints which are fast to chlorine. If aminodimethylviolanthrone (of. for. instance Annalen der Chemie 394: page 147) is used instead of ainian analogous dyestufi' is obtained. 0 l

. Emample 3 10 parts of mono-aminoviolanthrone cf.

Colour IndeXNo. 1102, and U; Al'Patents and 87 6,67 9 in fineststate of subdi 7 96,393 Vision are suspended in 100 parts of nitroben parts of sulfuric 1 SWITZERLAND, ASSIGNOB TO THE FIRM: SGCIETY At this temperature there are When all zene and the suspension is heated at about C. Through the mixture there are passed in a slow current, while stirring, and at about 95100 C., 8 parts of nitrosyl chloride. The

color of the suspension of the dyestuil changes 7 from green to black. After cooling the mixture of reaction is filtered, washed with a small quantity of nitrobenzene, then with alcohol, and finally thoroughly with boiling water. The dyestuff, when in a dry state, dissolves in boiling nitrobenzene with bright blue coloration and brownish-red fluorescence, in boiling Xylene with slightlyvioletcoloration and brownish-red fluorescence, and in boiling aniline with blue coloration. In concentrated sulfuric acid the dyestufi dissolves with bluish-red coloration. When poured into water there separate from this solution dark blue flocks. The dyestutl dyes cotton from a blue vat reddish-black tints which are fast to chlorine.

Ewamplc .4

10 parts of pure mono-aminoviolanthrone of. Colour Index No. 1102, and U. S. A. Patents 796,393 and 876,679 in finest state of subdivision are suspended in 500 parts of water, the suspension is treated with parts of pure hydrochloric acid and 85 parts of an aqueous solution containing lat parts of sodium nitrite, are introduced by and by while stirring, beneath the surface of the mistture. The whole is further stirred for some hours at ordinary temperature, air is blown through the mixture and the dyestuff filtered and washed thoroughly with boiling water. The new dyestutl dissolves in concentrated sulfuric acid with bluish-violet coloration; when poured into water there separate from this solution dark blue flocks. The dyestuff dissolves in boiling nitrobenzene with blue coloration and brownish-red fluorescence, in boiling xylene with violet coloration and brownish-red fluorescence, in boiling aniline with blue coloration. It yields a bright blue vat, dyeing cotton directly reddish-black tints.

What I claim is:

1. A process for the production ofvatdyestuffs by treating a mono-aniinoviolanthrone, the nuclear structure of which corresponds with the formula in liquid suspension with such oxidizing agents whlch may be employed in an acid medium.

2. A process for the production of vat dyestufis by treating the mono-aminoviolanthrone which is obtained by nitration and reduction of the violanthrone of the formula in aqueous suspension with such oxidizing agents which may be employed in an acid medium.

3. The herein described oxidation products of mono-aminoviolanthrones 0f the nuclear structure.

HUG-O SIEBENBllRGER. V 

